Diesel engine



J. W. LUTZ DIESEL ENGINE March 21, 1939.

Filed Dec. 24, 1936 V//I/////////////V/////////4 35 constructed as an insert of the piston. inner ur e of Cylinder head 2. 35

The invention will be described with reference In Figure 1 the piston 3 is on its upward stroke to.the accompanying drawing, in which:--- and the arrows show that the combustion air Figure 1 is a vertical section through a cylis being forced into combustion chamber secinder and piston embodying the invention and tion 31 I 40 showing the piston moving in an upward direc- In Figure 2 e P sto n its pw d movement 40 tion. has reached such position that throat 3m: is re- Patented Mar.21-,1939 2,151,218

UNITED, STATES PATENT OFFICE DIESEL ENGINE Johann Werner Lutz, Rheineck, Switzerland Application December 24, 1936, Serial No. 117,602

1 Claim. 123--32) The present invention relates to the combusterior of the piston combustion chamber to the tion chamber and means for effecting turbulency top of the piston wall for generating a turbuof the air for the combustion by special formalency around the combustion chamber. tions of the piston in which a combustion cham- Figure 6 is a top plan view of the piston illusber with a throat is formed, the characteristic of trated in Figure 5, showing by arrows the paths the invention being the provision of means by of the turbulence streams generated by the paswhich a high velocity of air is generated in the sage of air through the turbulence ports.

throat of the piston combustion chamber section, Figure 7 is a perspective view in longitudinal with attendant turbulency along the throat, as section through the upper portion of piston illusthe piston moves toward upper dead center. trated in Figures 5 and 6. '10

In one form of the invention, a member pro- Figure 8 is a vertical section through a modijecting inwardly from the wall closing the top fied structure which eliminates the member of the engine cylinder is formed and positioned shown in the preceding figures, or restricting so that as the piston moves toward upper dead the throat of the piston combustion chamber 1.) center, the said member restricts the throat of section. the piston combustion chamber section and air Figure 9 is a top plan view of the piston 8- is forced through the restricted throat into the trated in Figure 8. piston combustion chamber section, generating Figure 10 is a View f e oa es ct n a high velocity in the throat with a high degree m mb r p vi d wi h slo t enerate addiof turbulency along the throat. tional turbulence around the combustion chamber 20 Ports leading from the interior of the piston a scombustion section to the top of the piston may In Figures 1 t 4 u v I have illustrated a be employed to generate a turbulency around the Cylinder C d all its t p ,by e y d r h ad combustion chamber axis. In some cases, this W n the cylinder is po d a p will eliminate the necessity of an inwardly procatory pi on 3 in whic is sp d a c m 25 jecting member to restrict the throat area of the tion Chamber S o 3113 having an p n th oa piston combustion chamber section as hereinafter at 391$- e combust on Chamber Section 31! set forth. The throat restricting member may y be Sp elliptical. a y other suitbe formed with one or a, plurality of heli al able shape. Immediately above the throat 3x1: 0 straight or otherwise directed slots or bores in d removebly e y the y d ad 2 S -order to provide additional turbulency as ind a member adapted to restrict the throat as the cated at m, Figure 10. piston moves toward dead center, said member The combustion chamber section, the throat, in the present instance, being n injector nozzle or any other part of the said chamber, may be 4 h v n n extension :1: pr jectin below the Figure 2 is a section similar to Figure 1, showstricted, and in the continued movement of the ing the throat of the piston combustion chamber pi n he air i for ed thr u h he restricted restricted by means of a member such as an inthroat into the combustion chamber section 31B,

15 jector'nozzle, the piston not having reached final generating a high velocity in the throat with turposition. bulency of the air along the throat edge. This Figure 3 is a view similar to the preceding figrestricting action of member 4x makes possible ure, showing the piston at substantially upper the use of a throat area which is large compared dead center position. with the section of largest area through chamber Figure 4 is a perspective view in longitudinal 3.1:, taken perpendicular to the chamber axis. 50 section through the upper portion of the piston This large throat area is very desirable for small illustrated in the preceding figures. size engines where volume of the combustion Figure 5 is a view similar to Figure 3-, but showchamber is small, and it is especially important ing a. somewhat modified structure, the structure in high speed engines. The large throat is of including turbulence ports leading fromthe inalmost negligible throttling effect on the incom- 55 ing air during the greater part of the compression stroke and any material throttling takes place in the latter part of the compression stroke only,

when the member 4a: continues to restrict the throat area. The duration of such restriction will depend upon the protruding length of member 4.2:. The throator the nozzle, or both, may be shaped in any desired way in order to produce any kind of restricting action, as, for example,

a gradual restricting action or a constant action;

In addition to the turbulency along the throat edge, a turbulency around the combustion chamber longitudinal axis can be generated, if so desired, by providing the throat with properly,

disposed ports leading from the interior of member 3.1; to the top of the piston. As shown in Figures 5 and 6, these ports may be in the form of helically disposed slots at 5, Figures 5 and 6, or holes 6, as shown in said figures, or both.

Part of the air forced into the combustion chamber section 3:2: will pass through these slots or holes and thereby turbulence will be generated around the longitudinal axis of the combustion chamber as indicated by the arrows in Figures 6 and 7.

In Figure 7 a single helically cut slot is shown.

,In Figure 5 the cylinder head has been formed with an integral downwardly projecting combustion chamber restricting member 1 in which the injection nozzle 8 may be held if desired. The action of member I will be the same as that of member 4:: in the preceding figures.

In some cases the turbulence of the combustion air around the longitudinal axis of the combustion chamber section 3:: will be adequate without the necessity of the throat restricting member. In such case the width of the throat may be somewhat reduced over that shown in Figures 1 to 5 inclusive. Such a construction is shown in Figures 8 and- 9 in which a plurality of turbulence slots 9 are shown, these slots communicating the area above the piston with the interior of the combustion chamber section 311: in such manner that a whirling turbulence within the combustion chamber 'is created generally in the manner shown by the arrows in Figure 7.

It will be understood that various modifications may be made in the embodiments of the invention illustrated in the drawing without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is as follows:

In Diesel engines, means for creating combustion air turbulence comprising a cylinder and a cylinder closure, a piston having a combustion chamber formed as a surface of revolution in the piston head and having a restricted passageway in communication with the cylinder, said piston head being formed with a radially extending longitudinal slot cut through said piston head from said restricted passageway, said slot being exposed to the space formed between said piston head and said cylinder closure throughout its length and to said combustion chamber throughout its depth, and a projection extending into the cylinder and adapted to enter the restricted passageway of the piston head when the piston is nearing upper dead center position.

J OHANN WERNER LUTZ. 

